Title Picture

Pages

1 Aug 2014

Purple Swamphens – Sabkhat Al Fasl

We have two
subspecies or at least colour types of Purple Swamphen Porphyrio porphyrio
in Saudi Arabia, a grey-headed type from the eastern P. p. poliocephalus group
possibly P. p. seistanicus and blue-headed birds that may be P.
p. caspius, which is also often grey-headed, nominate or just be a colour variant of the grey-headed
birds?. The nominate subspecies probably does not occur this far east, at least
naturally, as birds from Israel are assigned to madagascariensis African
Swamphen with old records of caspius, but none recently, and if the nominate
occurred in Arabia you would expect it to have occurred in Israel as well. BWP
says nominate porphyryio group is restricted to countries bordering west Mediterranean,
well away from Arabia, although there is always a chance some escapes of the
nominate form have set up residence in the area? madagascariensis
African Swamphen does not appear to occur in eastern Saudi Arabia (although see
comments below from Qatar) as none of our blue headed birds have even the
slightest amount of green in the wing or on the mantle and are resident and
seen in all months. As caspius juveniles show green on the
scapulars it may be difficult to assign non green mantled birds to African Swamphen.
There is, however, at least one record of African Swamphen from Saudi Arabia
with one from the Red Sea coast at KAUST in 2013 which is the area you would
expect to see them as it closest to their known breeding range.

Due to the
confusion in the types occurring in Saudi Arabia I asked Neil Morris form
Qatar what the status was there. He mentioned that it is thought the Qatar
population, first recorded in March 2004, arose from the feral population in
UAE, with the resident Qatar birds being African (Green-backed) Swamphen Porphyrio
madagascariensis. Currently there is only one core population of about 15
pairs at Abu Nahkla, as other breeding sites at Sailiyah and Al Khor Reed Bed
have been destroyed. Abu Nahkla itself will be drained and developed in the
very near future, hence Qatar might lose this species altogether. Neill found the
first and only record of an unringed Grey-headed Purple Swamphen (as yet
unassigned to any particular race), showing no obvious signs of a captive
origin, feeding on the lawns of Al Corniche Park near the Sheraton Hotel from 5-23
September 2012. It was originally accepted onto the Qatar List in Category D, but
has recently been upgraded to Category A given that records were emerging of
birds passing through the Eastern Province of Saudi Arabia.

I also asked Mike
Pope from Kuwait the same question and he replied that the opinion was the 'blue-headed'
was the nominate and the 'grey-headed' the sub-species. Richard Bonser on a
visit to Kuwait some years ago suggested the Grey-headed birds were P. p.
seistanicus.

The subspecies that may occur as they are relatively close to the region are:

Birds are generally
listed occurring to groups, the nominate porphyrio group (porphyrio) the
madagascariensis (African Swamphen) group(madagascariensis) and
the poliocephalus (Grey-headed Swamphen)group (caspius,
seistanicus & poliocephalus). Members of the Grey-headed group seistanicus
& caspius are characterized on the basis of differences in average
size or subtle colour differences, so identifying these subspecies in the field
will be difficult. To confuse matters more several studies have shown that size
differences may be induced by environmental factors such as foodduring
the nestling stage and therefore, size differences alone is insufficient
evidence for the existence of taxa, suggesting there is insufficient basis for
the recognition of seistanicus & caspius as valid taxa.
Although it has been suggested that there are colour differences between
seístanicus & poliocephalus no diagnostic characters are known with
some authorities suggesting seistanicus & caspius are probably
best regarded as synonyms of poliocephalus.

What seems clear
to me is that the names that have been applied to the birds in the region may be
misleading as many of the subspecies are very similar and without morphological
data it will be difficult to sub-specifically identify them. Obvious African
Swamphens should not pose a problem but the Grey-headed birds should probably
be best left as birds of the poliocephalus (Grey-headed Swamphen)group
and the blue-headed birds left unassigned as they may be blue-headed birds of
one of the Grey-headed group or possibly nominate birds. If we can obtain more
details on the birds seen in Arabia, then a point raised by Neil would be very
interesting to study – “could we have a situation where 'Western'
Blue-headed Purple Swamphen, ‘Eastern’ Grey-headed Purple Swamphen and African
Green-backed Swamphen are three different species all occurring within the
region?”.

Saudi Arabia Flag

OSME Region

Google Translator

About The Blog

I hope you enjoy browsing my latest images & notes from the field, the majority are from Dhahran (eastern Saudi Arabia) as well as bird ringing in Bahrain. Most of the photographs are of birds but I will also include other interesting natural history shots when I take them.

About The Photographs

I am an amateur photographer who goes birdwatching and takes the occasional picture with birdwatching being my primary interest. I do birdwatch in an area that has good light for photogrpahy and manage to take quite a few photographs each day.

All photos on this blog are copyright and may not be copied or reproduced without my permission. Please ask if you would like to use any of my photographs for any reason.